CN105334684A - Projector and projection lens thereof - Google Patents

Abstract

The invention relates to a projector and a projection lens thereof, comprising an image light source generating device and a projection lens. The projection lens comprises a relay optical system and a projection optical system; the relay optical system comprises a focusing optical group and a condensing optical group, wherein the focusing optical group and the condensing optical group respectively comprise at least one lens; in addition, the focusing optical group can move between the condensing optical group and the image light source generating device; the projection optical system comprises a projection lens group and a reflecting mirror, wherein the projection lens group is positioned between the reflecting mirror and the relay optical system, and when the image light source generating device generates the image light beam, the image light beam passes through the relay optical system, penetrates through the projection lens group, is reflected by the reflecting mirror, reversely penetrates through the projection lens group and then is projected to the imaging surface.

Description

Projector and its projection lens

technical field

The invention relates to an optical projection device; in particular, it refers to a projector and a projection lens thereof.

Background technique

With the advancement of video technology, projectors are becoming more and more popular, and the projection lens used to clearly present images on the screen is one of the core components. With the limitation of the use of space, in order to achieve a clear projection effect in a small space, the projection lens of the projector is gradually designed in the direction of a short-focus projection lens, but in order to have a good projection effect in a short distance, short Focal lenses usually use a large number of lenses with large volume to achieve the effect of short focal length and high optical power.

As a result, the existing short-focus projection lens is not only bulky and heavy, but cannot achieve the miniaturized and lightweight design advocated today, but also because the internal lenses are both heavy and heavy, so it takes a long time to manufacture. It takes a long time to assemble, and its material cost is also relatively expensive.

And in order to improve the above-mentioned shortcoming, then some industry develops a kind of rear-projection type projector, promptly utilizes reflective mirror to reflect the image light beam of projector inside to be transmitted to the imaging plane, but this kind of model is because there is no focusing function, in the The setting can only be set at a fixed distance from the imaging surface, and the setting position cannot be changed according to different projection environments, thereby greatly reducing its applicability. Therefore, based on the above, it can be known that the known optical design of the projector and the projection lens is still not perfect, and needs to be improved.

Contents of the invention

In view of this, the purpose of the present invention is to provide a projector and its projection lens, which not only can effectively reduce the size and cost, but also have high optical performance, and can achieve the purpose of adjusting the focus, thereby increasing the projector's applicability.

To achieve the above object, the projector provided by the present invention includes an image light source generating device and a projection lens. Wherein, the image light source generating device is used to generate an image light beam. The projection lens is used to receive the image light beam and project it onto an imaging surface, and includes a relay optical system and a relay optical system arranged in sequence from a side close to the image light source generating device to a side far away from the image light source generating device Projection optical system; the relay optical system includes a focusing optical group and a condensing optical group, and the focusing optical group and the condensing optical group respectively include at least one lens, and the focusing optical group is larger than the condensing optical group close to the image light source generating device; in addition, the focusing optical group can reciprocate between the concentrating optical group and the image light source generating device, relative to the concentrating optical group; the projection optical system includes a projection mirror group and a reflector mirror, the projection mirror group is located between the reflector and the relay optical system, and the projection mirror group has a first optical surface and a second optical surface, and the first optical surface is closer to the second optical surface The concentrating optical group.

According to the above idea, the present invention also provides a projection lens for receiving an image beam and projecting it onto an imaging surface, and including a relay optical system and a projection optical system. Wherein, the relay optical system includes a focusing optical group and a converging optical group, and the focusing optical group and the converging optical group respectively include at least one lens, and the focusing optical group can move relative to the concentrating optical group . The projection optical system includes a projection mirror group and a reflector, the projection mirror group is located between the reflector and the concentrating optical group, and the projection mirror group has a first optical surface and a second optical surface, and The first optical surface is closer to the concentrating optical group than the second optical surface.

Thus, when the image light source generating device generates the image light beam, the image light beam passes through the focusing optical group and the condensing optical group in sequence, and enters the projection lens group from the first optical surface, and then passes through the first optical surface After the two optical surfaces leave the projection mirror group and are reflected by the reflector, the image beam enters the projection mirror group again from the second optical surface, and then leaves the projection mirror group from the first optical surface, and then projects to the image plane.

In this way, through the above-mentioned design, the volume and cost of the projector can be effectively reduced, and the projection lens can have high optical performance at the same time. In addition, the purpose of adjusting the focus of the projection lens can be achieved, thereby increasing the applicability of the projector.

Description of drawings

FIG. 1 is a structural diagram of a projector of the present invention;

Fig. 2 is the structural diagram of the projection lens of preferred embodiment of the present invention;

Figure 3 discloses that the image beam is projected to the imaging surface through the projection lens;

4A to 4D are graphs showing the relationship between the object distance and the lens distance.

【Symbol Description】

100 projectors

10 image light source generating device

P image beam

F Prism

20 projection lens

22 relay optical system

221 focusing optical group 222 the concentrating optical group

L1 shielding lens L2～L9 lens

24 projection optical system

G projection lens group

L10, L11 lens

S1 first optical surface S2 second optical surface

R mirror

200 curtains

D1～D4 distance

detailed description

In order to illustrate the present invention more clearly, a preferred embodiment is given hereby and detailed description is given below with illustrations. Please refer to FIG. 1 to FIG. An image light source generating device 10 and a projection lens 20 . The image light source generating device 10 is used to read image information from an image source, and has a prism F, and generates a corresponding image light beam P passing through the prism F according to the read image information. The projection lens 20 is used for receiving the image light beam P and projecting it to an imaging surface after undergoing optical processing with a predetermined effect. The projection lens 20 includes a relay optical system 22 and a projection optical system 24 sequentially arranged from a side close to the image light source generating device 10 to a side far away from the image light source generating device 10 . in:

Please refer to FIG. 2. In this embodiment, the relay optical system 22 includes a shielding lens L1, a shielding lens L1, and a Focusing optical group 221 and a light-condensing optical group 222 . The shielding lens L1 is located at the position where the projection lens 20 is closest to the image light source generating device 10. In addition to providing optical effects, it can also be used to prevent dust from entering the projection lens 20, and at the same time protect other aspects of the projection lens 20. The purpose of internal components. The focusing optical group 221 can move back and forth relative to the focusing optical group 222 between the focusing optical group 222 and the image light source generating device 10 to achieve the purpose of adjusting focus. In this embodiment, the focusing optical group 221 includes four lenses L2-L5 and an aperture ST, and the aperture ST is located between the lens L4 and the lens L5, and the lenses L2-L5 are respectively formed with different focusing lens groups, And can respectively move relative to this concentrating optics group 222 with different moving trajectories of other lens groups, and the described lenses L2～L5 of the present embodiment move with different trajectories according to different focal-object distances, so that they are compatible with adjacent components The curves of the distances between them can be seen from Figures 4A to 4D, and when the object distance is from 250 mm to 400 mm, the detailed data of the distances D1 to D4 between the lenses L2-L5 and the adjacent components are shown in the following table:

Object distance(mm) 250 275 300 325 350 375 400 Distance D1(mm) 14.482277 14.481682 14.506845 14.557766 14.634446 14.736884 14.865081 Distance D2(mm) -0.005251 0.167873 0.3 0.39113 0.441262 0.450398 0.418536 Distance D3(mm) 2.642403 2.569659 2.50671 2.453557 2.410198 2.376634 2.352866 Distance D4(mm) 2.619951 2.388488 2.200091 2.05476 1.952495 1.893296 1.877163

The function of the condensing optical group 222 is to transmit the image beam to the projection optical system 24 according to the required optical effect. In addition, in this embodiment, the concentrating optical group 222 includes four lenses L6-L9, and the upper parts of some of the lenses L6-L8 of the concentrating optical group are cut to make the lenses L6-L8 appear asymmetrical shape. Of course, in practical implementation, the lens numbers and lens shapes of the focusing optical group 221 and the condensing optical group 222 are not limited thereto, and can also be adjusted and changed according to different optical design requirements.

1 and 2, the projection optical system 24 includes a projection mirror group G and a mirror R, the projection mirror group G is located between the mirror R and the relay optical system 22, and includes a composite lens L10 and a single-layer lens L11, and the mirror surface of the composite lens L10 of the projection lens group G close to the relay optical system 22 is a first optical surface S1, and the mirror surface of the single-layer lens L11 close to the reflector R is a The second optical surface S2 makes the first optical surface S1 closer to the relay optical system 22 than the second optical surface S2. The mirror surface of the reflector R facing the projection mirror group G is a concave mirror and an aspherical surface. Of course, in practical implementation, the mirror surface of the reflecting mirror R facing the projection mirror group G can also be a spherical mirror surface or other free-form surfaces according to different optical requirements.

Therefore, please refer to FIG. 3 , and continue to refer to FIGS. 1 and 2 , when the image light source generating device 10 generates the image beam P, the image beam P enters the projection lens 20, and first passes through the shielding lens L1, the After the focusing optical group 221 and the condensing optical group 222, enter the projection lens group G from the first optical surface S1, leave the projection lens group G from the second optical surface S2, and pass through the reflector R After mirror reflection towards the projection mirror group G, the image light beam P enters the projection mirror group G again from the second optical surface S2, leaves the projection mirror group G from the first optical surface S1, and penetrates the projection mirror group G. After the lens L9 closest to the projection optical system in the condensing optical group is emitted from the projection lens 20, it is projected onto a curtain 200 (ie, the imaging plane).

It should be noted that the optical design of reflecting the image beam P through the reflector R of the above-mentioned projection optical system, and the projection mirror group G being repeatedly penetrated by the image beam P to achieve the secondary optical effect can be After reducing the size and volume of the lens, it can also effectively achieve the design of high optical performance, and then effectively achieve the effect of short focal length and miniaturization.

In addition, it can be seen from FIG. 2 that the number of optical elements (i.e. lenses L1-L9 and aperture ST) of the relay optical system 22 of the present invention is greater than the number of optical elements (i.e. lenses L10-L11 and reflectors) of the projection optical system 24. R), and the purpose of this design is to allow the image beam P to pass through the relay optical system 22 to produce better optical effects, and to provide good projection imaging when short-focus projection is provided. Effect.

Furthermore, the area through which the image light beam P is emitted from the first optical surface S1 is not larger than 1/2 of the area of the first optical surface S1 . In addition, in the last lens (i.e., lens L9) that the image beam P passes through before exiting the projection lens 20, the optical path before reflection and the optical path after reflection do not intersect, thereby avoiding optical interference and improving projection imaging the quality of. In addition, the reason why the above-mentioned lenses L6-L8 present an asymmetric shape is that the image beam reflected by the reflector R will not pass through the above-mentioned lenses, which can effectively avoid the situation of optical interference. occur, thereby achieving the effect of improving thinness and optical performance.

It must be noted that the above description is only a preferred embodiment of the present invention. For example, in other implementations, the shielding lens L1 can also be designed to be movable so that the projection lens 20 can be optically focused. The position can be closer to the optical path before reflection and the optical path after reflection do not intersect, thereby improving the focus and optical effect. In addition, all equivalent changes made by applying the scope of the description and claims of the present invention should be included in the patent scope of the present invention.

Claims (14)

1. A projector, characterized in that, comprising: an image light source generating device for generating an image light beam; and A projection lens is used to receive the image light beam and project it onto an imaging surface, and includes a relay optical system arranged in sequence from the side close to the image light source generating device to the side far away from the image light source generating device and A projection optical system; the relay optical system includes a focusing optical group and a condensing optical group, and the focusing optical group and the condensing optical group respectively include at least one lens, and the focusing optical group is larger than the condensing optical group The group is close to the image light source generating device; in addition, the focusing optical group moves back and forth relative to the focusing optical group between the focusing optical group and the image light source generating device; the projection optical system includes a projection lens group and a reflector mirror, the projection mirror group is located between the reflector and the relay optical system, and the projection mirror group has a first optical surface and a second optical surface, and the first optical surface is closer to the second optical surface the concentrating optical group; Thus, when the image light source generating device generates the image light beam, the image light beam passes through the focusing optical group and the condensing optical group in sequence, and enters the projection lens group from the first optical surface, and then passes through the first optical surface After the two optical surfaces leave the projection mirror group and are reflected by the reflector, the image beam enters the projection mirror group again from the second optical surface, and then leaves the projection mirror group from the first optical surface, and then projects to the image plane. 2. The projector according to claim 1, wherein at least one lens of the condensing optical group is a plurality of lenses, and the image beam is reflected by the reflector and leaves the first optical surface After the projection lens group, it also passes through some of the lenses in the concentrating optical group that are close to the projection lens group, and then projects onto the imaging plane. 3. The projector as claimed in claim 1 or 2, wherein the optical path before reflection and the optical path after reflection do not intersect each other when the image beam passes through the last lens projected to the imaging surface. 4. The projector as claimed in claim 2, wherein some of the lenses in the condensing optical group are asymmetrical in shape. 5 . The projector as claimed in claim 1 , wherein the area through which the image light beam passes when it exits from the first optical surface is not larger than 1/2 of the area of the first optical surface. 6 . 6. The projector as claimed in claim 1, wherein the projection lens further comprises a shielding lens, and the shielding lens is located between the focusing optical group and the image light source generating device. 7. The projector according to claim 1, wherein at least one lens of the focusing optical group is a multi-lens lens, and the focusing optical group also has an aperture, and the aperture is located on two of the focusing optical groups between the lenses. 8. A projection lens, characterized in that it is used to receive an image light beam and project it onto an imaging surface, and includes a relay optical system and a projection optical system, wherein: The relay optical system includes a focusing optical group and a converging optical group, and the focusing optical group and the converging optical group respectively include at least one lens, and the focusing optical group moves relative to the concentrating optical group; The projection optical system includes a projection mirror group and a reflector, the projection mirror group is located between the reflector and the concentrating optical group, and the projection mirror group has a first optical surface and a second optical surface, and The first optical surface is closer to the concentrating optical group than the second optical surface; Thus, when the projection lens receives the image beam, the image beam passes through the focusing optical group and the condensing optical group in sequence, and enters the projection lens group from the first optical surface, and then passes through the second optical After leaving the projection mirror group and reflecting through the reflector, the image beam enters the projection mirror group again from the second optical surface, and then leaves the projection mirror group from the first optical surface, and then projects to the imaging surface. 9. The projection lens as claimed in claim 8, wherein at least one lens of the focusing optical group is a plurality of lenses, and multiple groups of focusing lens groups are formed, and the focusing lens groups are different from other mirrors respectively. The moving locus of the group moves relative to the concentrating optical group. 10 . The projection lens according to claim 9 , wherein the focusing optical group further has an aperture, and the aperture is located between two lenses in the focusing optical group. 11 . 11. The projection lens according to claim 8, wherein some of the lenses in the light-condensing optical group are asymmetrical in shape. 12. The projection lens according to claim 8, further comprising a shielding lens, and the shielding lens is farther away from the focusing optics group than the focusing optics group, so that the focusing optics group is located between the shielding lens and the focusing optics between concentrating optical groups. 13. The projection lens as claimed in claim 8, wherein a mirror surface of the reflector facing the at least one lens is a concave surface. 14. The projection lens as claimed in claim 8, wherein the mirror surface of the reflector facing the at least one lens is an aspheric surface.